<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
    <a href="studyPlan/testHttpMessageDown?filename=1663710324.jpg" target="_blank" rel="noopener noreferrer">文件下载</a>
    <form action="studyPlan/download" method="post">
     <button type="submit" class="">Submit</button>
    </form>
</body>
</html>